Pre-shaped cervical pillows have been in existence for decades. It started as a therapeutic tool for orthopedic patients, and slowly expanded into consumer market particularly after the visco-elastic memory foam being commercialized. However, decades later, its popularity among average consumers is still limited. The current cervical pillows on the consumer market take a universal single pillow pad construction with two most popular configurations. In one configuration, the pillow has a flat bottom surface, while its upper surface has two lobes protruded upwards, differing in radius/height, disposed along the two longitudinal sides with a trough in between. The lobes are intended to support the neck, whereas the trough is to support the head of a user. In another configuration, the bottom surface of the pillow images its upper surface, so that the pillow is peanut-shaped in its side view. By inverting the pillow pad to switch its longitudinal sides, either configuration provides two positions with two different contoured curvatures/heights for a user to choose from regardless the fact that an optimal alignment of a user's head, neck, and shoulder during sleep varies depending on the user's body size and sleeping position, and that the variations in body size among population and between genders are quite significant. This “two-sizes-fit-for-all” approach certainly has not helped to encourage consumers to embrace the cervical pillows having been on the consumer market so far.
Prior art in adjusting pre-shaped or flat foam pillows in elevation, inclination, cervical support, and firmness of head support surface to fit users with different sleeping positions and different body sizes exists:
U.S. Pat. No. 3,775,785 is directed to an adjustable pillow apparatus having a pair of pillow sections with each having a wedge shaped portion to which removable attachment means is attached so that the pillow sections can be adjusted along their wedge shaped portions to vary the height of the pillow.
U.S. Pat. No. 4,756,090 is directed to an orthopedic pillow having a block made of deformable material, the block having a substantially quadrilateral perimeter, an upper surface of the block having a substantially airfoil-shaped reverse curved surface; and a sizing kit with ordered multiplicity of members for determining an appropriate size of orthopedic pillow for use by a patient.
U.S. Pat. No. 5,537,703 is directed to a multi-position pillow, the construction of which includes a first main face having an essentially planar main surface with a head receiving recess; and a second main surface located opposite the first main face with a plurality of extending fingers arranged in rows. Several recesses are defined in the area between a finger and the surrounding, adjacent fingers of the second main face. The first surface of the pillow provides a relatively firm support, while the second surface of the pillow is convoluted to provide relatively soft support.
U.S. Pat. No. 5,926,879 is directed to a cervical pillow with an insert and lobe of sufficient curvature to enable the user to obtain the intended firmness effects. Formed within the lobe is an opening which has an insert shaped and dimensioned for snug contact therein. The pillow may be reversible and placed on top of a mating pillow wedge positioned between the trough formed between the lobes to provide support for a user when reading, watching T.V., or participating in other activities.
U.S. Pat. No. 6,327,725 is directed to an orthopedic pillow, the body of which is comprised of pre-formed visco-elastic foam with an interior longitudinal cavity disposed near the edge of the pillow on which a user's neck is intended to rest. An inflatable airtight chamber is disposed within the cavity for providing adjustable support to the user's neck. The level of neck support can be adjusted using a hand-operated pump.
U.S. Pat. No. 4,914,763, No. 5,016,303, No. 5,163,194, No. 5,732,427, No. 5,926,880, No. 5,937,460, No. 6,006,380, No. 6,151,733, No. 6,345,401, No. 6,981,288, and No. 7,013,512 are directed to a type of adjustable foam pillows having a construction of multiple removable/changeable components. The adjustment, mostly in heights either for the whole pillow or for the head or neck support area, can be achieved by inserting or removing selected component(s) to customize the pillow for a user.
In addition, U.S. Pat. No. 4,914,763, No. 5,953,777, No. 5,987,676, and No. 6,895,619 are directed to another type of adjustable foam pillows having a plurality of components (or a single component that can be folded into multi-layers) with generally large flat supporting surfaces. A pillow can be constructed by stacking a selected number or type of these components (or folding into certain layers) to adjust the height of the whole pillow or the firmness of its support surface to fit for a particular user and his/her sleeping position.
The prior art described above teaches a variety of cervical foam pillow devices with various methods of customizing a pillow device for a particular user, each with its unique virtue and accompanied with its own limitations. In general, pillow devices having desirable adjustability and adjustable features contain multiple components, usually more than two, and are relatively cumbersome to dispose and adjust. On the other hand, pillow devices with simple construction and relatively easy to adjust usually have limited adjustability in positions and/or adjustable features.